This project in cancer-oriented organic chemistry is concerned with two broad areas, the still obscure connection between them and, as relevant, the chemistry of the compounds involved: (1) Carcinogenesis-- Synthesis of metabolites, or suspected metabolites, of carcinogens and activated forms of carcinogenic arylamines, azo dyes, etc. These include ring-substituted thiomethyl, cysteinyl, homocysteinyl, and tyrosyl derivatives, as well as the N-hydroxylated (or N-OCOR) form of the carcinogenic arylamide. New carcinogens with electrophilic centers will be sought. All of this is aimed at elucidating the mechanisms of carcinogenesis and ultimately control of cancer in humans. (2) Carcinostasis--Development of two series of compounds, some of which have already been found by NSC to have good tumor-inhibiting activity: (a) polyhalogenated fluorenes including 2,4,7-trichlorofluorene (which is definitely non-carcinogenic), and (b) some new benzanilide nitrogen mustards. Also new areas are being explored for compounds with good carcinostatic properties. (3) New chemistry--Particularly as relevant to the biological studies and to find structure-activity relationships. This include work on N-mustards, maleisoimides, fluorenylides, aryl substitution, azo dyes, etc.